In many roofing applications, for example in large, flat commercial roof decks, a roofing membrane is used to seal and protect the roof deck from environmental weather conditions. The roofing membrane may be made of various materials, such as polymeric materials including EPDM (ethylene propylene diene M-rubber) or TPO (thermoplastic polyolefin). The roofing membrane is adhered overtop insulation boards or cover boards. The insulation boards are typically secured to the roofing substrate or roof deck via an adhesive composition. A conventional adhesive composition used to adhere the insulation boards to the roof deck, or used to adhere roofing membranes to rigid insulation boards, cover boards, or directly to the roof deck, includes polyurethane. The polyurethane adhesives are oftentimes applied directly onto the roof deck via an applicator system and the insulation boards are then laid onto the roof deck surface. Conventional polyurethane adhesives oftentimes include two separate parts that are mixed by an applicator just prior to being applied onto the surface of the roof deck. The two parts include an isocyanate blend and a polyol blend. Upon mixing, the isocyanate blend reacts or crosslinks with the polyol blend to form the polyurethane adhesive.
These conventional two-part polyurethane adhesives must be packaged into separate containers to prevent mixing of the adhesive parts prior to application. In certain configurations, the adhesive parts are packaged into a single system having divided, separately sealed sides for storing the adhesive parts. Upon removal of a port cap, the adhesive sides communicate with an attached nozzle. However, if the nozzle is attached and then stored, it is possible for the adhesive parts to drain into the nozzle prior to application, crosslink, and plug the nozzle or the package with cured polyurethane. One solution is to place a membrane overtop the port but underneath the port cap. However, this membrane may become ruptured or pierced during shipping and handling or during removal of the port cap, thus defeating the purpose of the membrane. In other cartridge configurations, plugs are inserted into the ports or molded over the ports to seal the contents of the cartridge during storage and transportation. Prior to application the plugs are removed and the mixing nozzle is attached. Therefore is also possible for adhesive components to prematurely dispense and mix if the cartridge and mixing nozzle are stored with the plugs removed. Therefore, there is a need in the art to provide an adhesive packaging system that prevents unwanted mixing of the adhesive parts prior to application on a substrate, but after the attachment of the mixing nozzle, and allows for the use of port caps, port plugs, or both without rupturing the membrane.